Development of ‘green’ catalysis: a chiral phase-transfer catalyst for michael reactions, and peracetic acid as an atom-economical reagent for acetoxylation reactions
File(s)
Author(s)
Bagale, Sharanappa Maduraya
Type
Thesis
Abstract
Green catalysis for chemical transformations is gaining increasing attention due to its role in sustainable chemical processes that efficiently utilize renewable raw materials, minimize unwanted by-products, and avoid the use of hazardous and toxic chemicals. This thesis explores the development of green catalysis. In the first part of the research project, new catalytic protocols were developed for the asymmetric Michael addition of glycinate Schiff base to arylidene malonates by a Methylene Bridged Bis(imidazoline) (MBI) derived 2-oxopyrimidinium salts as phase transfer catalysts (PTCs) to form optically active Michael products. These products are vital precursors for the synthesis of pharmaceuticals, agrochemicals; and other high-tech materials. In the second part, a Pd catalyst system was developed for the oxidation reactions.
In the first chapter, key advances made in the asymmetric catalysis of Michael addition of glycinate to alkylidene malonate are presented and compared. It also provides comprehensive and critical information on the scope and limitations of different organocatalysts. Then, it discusses the aim of the PhD research.
The second chapter involves the result and discussion of the asymmetric Michael addition. This part includes the synthesis of PTCs, Schiff base, and arylidene malonates. This part then presents solvent optimizations for an enantioselective Michael reaction, conclusion, and future work.
The third chapter presents the literature survey of oxidative C-H bond oxidative acetoxylation. Various protocols that have been used for acetoxylation were compared and critically analyzed concerning their strengths and limitations. Then it covers the aim of the study. The second part includes the synthesis of oxime ether substrates for acetoxylation, results that are discussed and compared to the literature data. Finally, it presents a conclusion and future work for the acetoxylation of the C-H bond.
The last chapter details the experimental procedures and characterization data for the compounds synthesized in this research project.
In the first chapter, key advances made in the asymmetric catalysis of Michael addition of glycinate to alkylidene malonate are presented and compared. It also provides comprehensive and critical information on the scope and limitations of different organocatalysts. Then, it discusses the aim of the PhD research.
The second chapter involves the result and discussion of the asymmetric Michael addition. This part includes the synthesis of PTCs, Schiff base, and arylidene malonates. This part then presents solvent optimizations for an enantioselective Michael reaction, conclusion, and future work.
The third chapter presents the literature survey of oxidative C-H bond oxidative acetoxylation. Various protocols that have been used for acetoxylation were compared and critically analyzed concerning their strengths and limitations. Then it covers the aim of the study. The second part includes the synthesis of oxime ether substrates for acetoxylation, results that are discussed and compared to the literature data. Finally, it presents a conclusion and future work for the acetoxylation of the C-H bond.
The last chapter details the experimental procedures and characterization data for the compounds synthesized in this research project.
Version
Open Access
Date Issued
2024-09-22
Date Awarded
01/05/2025
Advisor
Hii, King Kuok (Mimi)
Publisher Department
Department of Chemistry
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)